Contractor named to design and build new elevated roadway

OSO – Following a moment of silence at noon Saturday, May 31, State Route 530 will reopen to traffic, re-establishing a critical link between the communities of Arlington, Oso and Darrington. The highway has been closed for more than two months while crews worked to clear a devastating landslide that covered a mile of the rural corridor.

“Our mission was to reconnect communities who have already lost so much, and do it in a respectful manner,” said Washington State Department of Transportation Regional Administrator Lorena Eng. “This would not have been possible without the help of dedicated staff from both WSDOT and our contractors.”

Contractor crews from IMCO Construction worked around the clock to remove roughly 90,000 cubic yards of material that blanketed the highway March 22. Crews are able to reopen the road a week earlier than planned, and at least $1.5 million under the original contract amount of $4.9 million.

“We are all heavy-hearted to be involved in the disaster that is the SR 530 landslide,” said Tyler Kimberley, president of IMCO Construction. “Witnessing the devastation and working side by side with the grieving communities has been life changing.”

Environmental Science Associates (ESA) implemented the material-removal plan crafted by WSDOT and Snohomish County, ensuring any items uncovered were handled respectfully. Many of those hired by ESA were from local communities and had assisted during search-and-recovery operations.

Granite Construction Inc. was hired to pilot traffic to and from Darrington around the clock along the Seattle City Light access road. With a set schedule for travel in both directions, Granite provided much-needed relief to local residents, as the alternative was a long detour around the closed portion of SR 530 that added hours to their commutes and created additional hardships.

Rules of the roadThere will not be enough room to safely allow two lanes of traffic on SR 530 when it reopens Saturday.

Drivers will continue to be piloted eastbound and westbound.

There will be no prescribed schedule: Flaggers will alternate directions based on demand.

The speed limit will be 25 mph.

Gravel covers about 600 feet of road in a section discovered to be missing when slide material was removed.

Next stepsWSDOT has awarded the design/build contract to Guy F. Atkinson Construction in the amount of $20.57 million to construct a new portion of SR 530 through the slide area. Due to the flood risk resulting from the landslide and the geographic changes to the Stillaguamish River North Fork, the roadway must be elevated.

Periodically during construction, traffic will return to the Seattle City Light access road.

WSDOT and the design/build contractor will host a community meeting in mid-June.